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author | kaashoek <kaashoek> | 2006-09-06 15:32:21 +0000 |
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committer | kaashoek <kaashoek> | 2006-09-06 15:32:21 +0000 |
commit | 21a88dd053069c17b619a89bf2c8beefb672fcd5 (patch) | |
tree | c5cf276383153f6dea006e2abdccc1e6d11d1b41 /sh.c | |
parent | d49a2d53867b2b3a7d627be217c12b3a95676766 (diff) | |
download | xv6-labs-21a88dd053069c17b619a89bf2c8beefb672fcd5.tar.gz xv6-labs-21a88dd053069c17b619a89bf2c8beefb672fcd5.tar.bz2 xv6-labs-21a88dd053069c17b619a89bf2c8beefb672fcd5.zip |
some pipe support in sh
bug in proc_wait
Diffstat (limited to 'sh.c')
-rw-r--r-- | sh.c | 202 |
1 files changed, 129 insertions, 73 deletions
@@ -7,21 +7,28 @@ #define BUFSIZ 512 #define MAXARGS 10 #define MAXNODE 2 +#define MAXCMD 2 -// only allocate nodes for i/o redir; at some point we may have to build a -// a real parse tree. -struct node { +// an embarrassingly naive shell + +// some day a real parse tree; for now ad-hoc +struct ionode { int token; char *s; }; -struct node list[MAXNODE]; -int nextnode; +struct ionode iolist[MAXNODE]; +int nextio; -char buf[BUFSIZ]; -char *argv[MAXARGS]; -char argv0buf[BUFSIZ]; -int argc; +struct cmd { + char *argv[MAXARGS]; + char argv0buf[BUFSIZ]; + int argc; + int token; +}; +struct cmd cmdlist[MAXCMD]; +int nextcmd; +char buf[BUFSIZ]; int debug = 0; int parse(char *s); @@ -29,7 +36,7 @@ void runcmd(void); int ioredirection(void); int gettoken(char *s, char **token); int _gettoken(char *s, char **p1, char **p2); -void addnode(int token, char *s); +void addio(int token, char *s); int main(void) @@ -48,21 +55,25 @@ int parse(char *s) { char *t; - int c; + int c, i; gettoken(s, 0); - argc = 0; - nextnode = 0; + nextio = 0; + nextcmd = 0; + for (i = 0; i < MAXCMD; i++) { + cmdlist[i].argc = 0; + cmdlist[i].token = 0; + } while (1) { switch ((c = gettoken(0, &t))) { case 'w': // Add an argument - if (argc == MAXARGS) { + if (cmdlist[nextcmd].argc >= MAXARGS) { printf(2, "too many arguments\n"); return -1; } - argv[argc++] = t; + cmdlist[nextcmd].argv[cmdlist[nextcmd].argc++] = t; break; case '<': // Input redirection @@ -71,7 +82,7 @@ parse(char *s) printf(2, "syntax error: < not followed by word\n"); return -1; } - addnode('<', t); + addio('<', t); break; case '>': // Output redirection @@ -80,7 +91,13 @@ parse(char *s) printf(2, "syntax error: > not followed by word\n"); return -1; } - addnode('>', t); + addio('>', t); + break; + + case ';': // command sequence + case '|': // pipe + cmdlist[nextcmd].token = c; + nextcmd++; break; case 0: // String is complete @@ -98,88 +115,127 @@ parse(char *s) void runcmd(void) { - int i, r, pid; + int c, i, r, pid, tfd; + int fdarray[2]; // Return immediately if command line was empty. - if(argc == 0) { + if(cmdlist[0].argc == 0) { if (debug) printf(2, "EMPTY COMMAND\n"); return; } - // Clean up command line. - // Read all commands from the filesystem: add an initial '/' to - // the command name. - // This essentially acts like 'PATH=/'. - if (argv[0][0] != '/') { - argv0buf[0] = '/'; - strcpy(argv0buf + 1, argv[0]); - argv[0] = argv0buf; - } - argv[argc] = 0; + for (c = 0; c <= nextcmd; c++) { + // Clean up command line. + // Read all commands from the filesystem: add an initial '/' to + // the command name. + // This essentially acts like 'PATH=/'. + if (cmdlist[c].argv[0][0] != '/') { + cmdlist[c].argv0buf[0] = '/'; + strcpy(cmdlist[c].argv0buf + 1, cmdlist[c].argv[0]); + cmdlist[c].argv[0] = cmdlist[c].argv0buf; + } + cmdlist[c].argv[cmdlist[c].argc] = 0; - // Print the command. - if (debug) { - printf(2, "[%d] SPAWN:", getpid()); - for (i = 0; argv[i]; i++) - printf(2, " %s", argv[i]); - for (i = 0; i < nextnode; i++) { - printf(2, "%c %s", list[i].token, list[i].s); + // Print the command. + if (debug) { + printf(2, "[%d] SPAWN:", getpid()); + for (i = 0; cmdlist[c].argv[i]; i++) + printf(2, " %s", cmdlist[c].argv[i]); + for (i = 0; i < nextio; i++) { + printf(2, "%c %s", iolist[i].token, iolist[i].s); + } + printf(2, "\n"); } - printf(2, "\n"); - } - - if (strcmp(argv[0], "/cd") == 0) { - if (debug) printf (2, "/cd %s is build in\n", argv[1]); - chdir(argv[1]); - return; - } - pid = fork(); - if (pid == 0) { - if (ioredirection() < 0) - exit(); - if ((r = exec(argv0buf, (char**) argv)) < 0) { - printf(2, "exec %s: %d\n", argv[0], r); - exit(); + if (strcmp(cmdlist[c].argv[0], "/cd") == 0) { + if (debug) printf (2, "/cd %s is build in\n", cmdlist[c].argv[1]); + chdir(cmdlist[c].argv[1]); + return; } - } - if (pid > 0) { - if (debug) - printf(2, "[%d] WAIT %s\n", getpid(), argv[0]); - wait(); - if (debug) - printf(2, "[%d] wait finished\n", getpid()); + if (cmdlist[c].token == '|') + if (pipe(fdarray) < 0) + printf(2, "cmd %d pipe failed\n", c); + + pid = fork(); + if (pid == 0) { + if (cmdlist[c].token == '|') { + if (close(1) < 0) + printf(2, "close 1 failed\n"); + if ((tfd = dup(fdarray[1])) < 0) + printf(2, "dup failed\n"); + if (close(fdarray[0]) < 0) + printf(2, "close fdarray[0] failed\n"); + if (close(fdarray[1]) < 0) + printf(2, "close fdarray[1] failed\n"); + } + if (c > 0 && cmdlist[c-1].token == '|') { + if (close(0) < 0) + printf(2, "close 0 failed\n"); + if ((tfd = dup(fdarray[0])) < 0) + printf(2, "dup failed\n"); + if (close(fdarray[0]) < 0) + printf(2, "close fdarray[0] failed\n"); + if (close(fdarray[1]) < 0) + printf(2, "close fdarray[1] failed\n"); + } + if (ioredirection() < 0) + exit(); + if ((r = exec(cmdlist[c].argv0buf, (char**) cmdlist[c].argv)) < 0) { + printf(2, "exec %s: %d\n", cmdlist[c].argv[0], r); + exit(); + } + } else if (pid > 0) { + int p; + if (debug) + printf(2, "[%d] FORKED child %d\n", getpid(), pid); + + if (c > 0 && cmdlist[c-1].token == '|') { + close(fdarray[0]); + close(fdarray[1]); + } + if (cmdlist[c].token != '|') { + if (debug) + printf(2, "[%d] WAIT for children\n", getpid()); + do { + p = wait(); + if (debug) + printf(2, "[%d] WAIT child %d finished\n", getpid(), p); + } while (p > 0); + if (debug) + printf(2, "[%d] wait finished\n", getpid()); + } + } } } int ioredirection(void) { - int i, fd, dfd; + int i, fd; - for (i = 0; i < nextnode; i++) { - switch (list[i].token) { + for (i = 0; i < nextio; i++) { + switch (iolist[i].token) { case '<': if (close(0) < 0) printf(2, "close 0 failed\n"); - if ((fd = open(list[i].s, O_RDONLY)) < 0) { - printf(2, "failed to open %s for read: %d", list[i].s, fd); + if ((fd = open(iolist[i].s, O_RDONLY)) < 0) { + printf(2, "failed to open %s for read: %d", iolist[i].s, fd); return -1; } if (debug) - printf(2, "redirect 0 from %s\n", list[i].s); + printf(2, "redirect 0 from %s\n", iolist[i].s); break; case '>': if (close(1) < 0) printf(2, "close 1 failed\n"); - if ((fd = open(list[i].s, O_WRONLY|O_CREATE)) < 0) { - printf(2, "failed to open %s for write: %d", list[i].s, fd); + if ((fd = open(iolist[i].s, O_WRONLY|O_CREATE)) < 0) { + printf(2, "failed to open %s for write: %d", iolist[i].s, fd); exit(); } if (debug) - printf(2, "redirect 1 to %s\n", list[i].s); + printf(2, "redirect 1 to %s\n", iolist[i].s); break; } } @@ -187,16 +243,16 @@ ioredirection(void) } void -addnode(int token, char *s) +addio(int token, char *s) { - if (nextnode >= MAXNODE) { - printf(2, "addnode: ran out of nodes\n"); + if (nextio >= MAXNODE) { + printf(2, "addio: ran out of nodes\n"); return; } - list[nextnode].token = token; - list[nextnode].s = s; - nextnode++; + iolist[nextio].token = token; + iolist[nextio].s = s; + nextio++; } |